Where's the saving?

4 June 2008

You reported on the VPhase energy consumption reducing device (News, 19 May).

As the major power consumers in the household are likely to be heating and lighting, a reduction in the voltage will not produce energy savings. Electric heating will need to be on longer to achieve the desired heat output. Incandescent lighting becomes more inefficient as the voltage is reduced, wasting even more energy as heat.

We do not expect the fridge to get colder with a higher supply voltage, but we are interested in the energy consumption to maintain the target temperature. While reducing energy consumption is a laudable aim, I don’t think this device will do as much as your article suggests.

Mark Boult

Fillongley